Hi,


ECU gives check engine light with the 'low alternator voltage' problem on a Bugeye WRX.

Battery replaced and now holds charge, alternator is fine - checked battery with and without ignition on with a multimeter. 12v-ish without ignition and 13.5v approx with iginition.

Car starts fine after long periods so can't be a battery issue.

Any ideas guys?!

 

Have you had both checked prfoessionally? They will do it under load conditions, and it can make a huge difference.

 

So the battery voltage is raising with ignition on? or is that the wrong way round? or do you mean with engine running?

Whats the vottage at battery with engine running and lights on